Pneumatically operated tool



1952. c. H. YOUNG 3,048,150

PNEUMATICALLY OPERATED TOOL Filed Sept. 23, 1960 2 Sheets-Sheet l IN VEN TOR. 0/4/94 5 H. YOUNG A r TOR/V5) 1962 c. H. YOUNG 3,048,150

PNEUMATICALLY OPERATED TOOL Filed Sept. 23, 1960 2 Sheets-Sheet 2 IN VENTOR. CHARLES/I ou/v6 A TTOPNEY @ili ce 3,048,150 Patented Aug. 7, 19623,043,150 PNEUMATICALLY OPERATED TOOL Charles H. Young, Cleveland, Ohio,assignor to Herschel Products, Inc., Cleveland, Ohio, a corporation ofOhio Filed Sept. 23, 1960, Ser. No. 57,982 11 Claims. (Cl. 121-33) Thisinvention relates to portable pneumatically operated power tools andmore particularly to the type which may be grasped and controlled by theoperator in use, such as grinders, sanders, etc. employed in light andmedium duty Work.

'It is one of the objects of this invention to provide an effective andpositive governor unit for insuring safe and accurate tool speedcontrol.

Another object of the invention is a fluid motor substantially free ofvibration in operation mounted in a one-piece high strength light metalhousing to provide comfortable handling of the tool and safety to theoperator.

A further object of this invention is a tool of this character havingprovisions for automatic lubrication from a relatively large oilreservoir in one of the tool handles.

Still another object of this invention is a fluid motor unit which iscompletely and easily removable from the tool housing without thenecessity of first removing a housing cap and attendant bolts or screws.

Another object of the invention is to enable the operator to adjust andreset the motor idling speed without the necessity for taking the toolapart or to remove the governor unit from the housing.

A further object is a simplified overall construction which is easy toassemble and disassemble and which adapts the tool for working inlimited or close quarters.

A further object of the invention is to reduce maintenance costs andidle time for replacements or adjustments and thereby to enable theoperator to increase production at a lower cost.

A still further object is to prevent waste of compressed air or otherfluid in the operation of the tool by means of a compact leakproof andsimplified construction.

Another object is to insure free valve action by providing a positiveplunger type throttle control for actuating the throttle valve.

Other objects and advantages of this invention will become more apparentas the following description of an embodiment thereof progresses,reference being made to the accompanying drawing in which like referencecharacters are employed to desginate like parts throughout the same.

In the drawings:

FIGURE 1 is a top plan view of a tool embodying my invention, one of thehandles of which is shown in section;

FIGURE 2 is an enlarged section taken on line 2-2 of FIGURE 1;

FIGURE 3 is a view taken in the direction of line 3--3 of FIGURE 2;

FIGURE 4 is a transverse section taken on the line 44 of FIGURE 2;

FIGURE 5 is a transverse view taken on the line 5-5 of FIGURE 2;

FIGURE 6 is a front elevation of the fluid motor, tool spindle andassociated governor unit.

In carrying out myinvention as illustrated in the embodiment shown inthe drawings, a motor housing generally indicated at 1 is an integralstructure of cylindrical form closed at its top, as at 2, and having anopen bottom end through which the motor and governor assembly isinstalled or removed.

A pair of hollow handles 3 and 4 are secured to the body and extendradially outwardly thereof, the main handle 3 having a threaded inletbushing 5 located in its free end for connection with a live compressedair line and houses the throttle valve assembly, while the hollow handle4 serves as a lubricant reservoir for feeding lubricant to the interiorof the housing.

The throttle valve assembly includes a valve head 6 normally seated on avalve seat 7 and urged to seating position by a coil compression spring8 having its ends respectively in engagement with the valve head 6 andthe spring cap 9. A loop 10 carried by the valve housing 11 engages thecap 9 to normally place the spring under compression.

Valve body 11 is press fitted with nipple 17 and has a forward portioncontaining bores 12 which communicate with the opening 13 in the valveseat and with the space 14 and duct 15 leading into the upper part orgovernor section of the housing 1. The body 11 has an annular flange 16which rests against the free end of the threaded nipple 17, as shown inFIGURE 2.

Valve head 6 is provided with a plunger stem or pin 18 which extends andoperates through the opening 19 in the throttle valve bushing 20, theforward end of the stem at 21 extending into the bushing 22 to normallyengage the reduced portion 23 of the valve control plunger 24, when thevalve 6 is seated in the seat 7.

The valve control plunger 24 has an enlarged portion 25 on each side ofthe reduced portion and these portions 25 have a snug axial sliding fitwithin the bushing 22 for guiding the plunger, there being a head orfinger grip 26 at one terminal end of the plunger by which the plungermay be moved axially in the bushing to actuate the stem 18 andconsequently seat or unseat the valve 6. The end of the stem 18 isrounded to ride along the inclined surface 27 when the plunger isoperated in either direction. A spring urged ball and detent at 28 and29, respectively, serve to properly locate and limit the plungermovement.

The bore of the housing 1 is provided with a liner 30 which has a boreWhose axis is eccentric to that of the bore of the housing 1 as clearlyshown in FIGURES 4 and 5. The motor rotor 31 is thus eccentrieallymounted to rotate within the line and at one point is only a fewthousandths of an inch clearance of touching the liner bore as at 32while the space at all other points between the rotor and linerprogressively increase to a maximum and thence to a minimum as the rotormakes each revolution from the point 32.

The rotor is preferably integral with the output shaft 33. This shaftextends upwardly from the rotor as at 34 through a top end plate 35 andbearing 36 and downwardly through a bottom end plate 37, hearing 38,bearing lock nut 39 and the wheel collar 40.

The rotor is provided with a plurality of bores or ducts 41 extendingthrough the top and bottom thereof spaced apart circumferentially in therotor and communicating with openings or ducts in the top and bottom endplates 35 and 37, respectively, as will presently appear.

The rotor is also slotted radially inwardly from its outer surface as at42 to receive and to provide guides for the rotor blades 43. These slotsalso extend from the top to the bottom of the rotor and also communicatewith openings or ducts in the top and bottom plates 35 and 37,respectively, as will also appear later on. The arrangement of thelongitudinal slots 42 with respect to the ducts 41 is such that theslots and ducts alternate with each other around the rotor body but donot communicate directly one with another.

The rotor is also provided with slots 44 arranged respectively betweenthe slots 42 but which do not extend to the top and bottom end plates,being limited'in extent for a distance intermediate the top and bottomend plates of the rotor. These slots 44 each communicate with therespective ducts 41.

The rotor liner is provided with a plurality of exhaust slots arrangedto extend circumferentially of the liner and spaced from one another ina direction which is axial to the liner 30 itself. It will be noted inFIGURE 6 that the slots 45 are arranged in two overlapping groups, as atG and G Group G is the primary or initial exhaust group, being the firstto exhaust the air fromthe motor as it runs in the direction of thearrow, FIGURE 5,

' while group G as the secondary group, permits final downward: pressureon the governor wearplate54 which I,

, is seated on the governor bottom plate 48;

The plate 48 is slotted radially inwardly at spaced intervals from itsperiphery as at 80, and these slots are positioned to-pass over theopeningsfil) in the top end pressure from the governor chamberprogressively into,

the ducts 41 and the slots 42 as the rotor moves in the direction of thearrow, FIGURE 5, from the. point 32.

e The under surface of the plate '35 is relieved, asat 61,

forming a recess connecting the lower ends of'the openings so that fluidpressure entering frorn'the governor chamber past the wear plate 54 andbottom governor plate 35 will be directed through the openings and intothe recess 61.

The bottom end plate 37 is also provided with an arcuate relieved recess62 opening upwardly against the bottom surface of the rotor 31. Thisrecess 62 and the recess 61 in the top end plate 35 are in alignmentvertically through the rotor. The recess '62 is a containment for fluidpressure as the slots 42 and ducts pass over it during rotation of therotor and thus provides a cushion or equalizing means for the fluidpressure exerted in the slots and ducts.

In each of the slots 42 is a free floating rotor blade 43 which hassliding movement radially of the slot and which hasa rear edgepreferably curved as at 63 on substantially the same radius as that ofthe rear wall 64 of the slot, and which has a forward straightedge 65parallel with and adapted to have contact with the vertical innercylindrical wall of the liner 30.

plate as the rotor. and governor unitrevolves, and help to maintainanelfective balance of fluid flow at governed rotor speeds.

The governor body 49, to which the top plate 47 is secured by the screws50, is threaded at Slalong its stem into the'upper threaded portion ofthe rotor. As the rotor rotates in the direction of the arrow as showninFIGURE '5, a left handthread is employed at 81, but itislunderthepoint 32. I

An axial opening in the body 49 slidably carries a pin 82 (securedtherein by a press fit), the upper end of the pin projecting above thebody and is secured in a recess 83 in the governor bottom plate by apress fit, the bottom end of the pin 82 engaging a coil compressionspring 84 in the opening 85 extending through the rotor spindle. Thecompression ofthe spring against the pin 82 is adjusted by means or" anadjusting screw 86 threaded into the lower end of the rotor spindle. I

It will be seen from the above descriptionthat as the rotor and governorunitbegin to operate under the influ ence of the high pressure incomingfluid, centrifugal force tends to draw the governorweights 51'outwardlyabout their axes defined by the weight pins 52.

In order that the several units, i.e., the rotor-governor 7 unit, thetop and bottom end plates 35 and 37, respectively, and the rotor liner30 may be properly positioned and assembled together in exactoperatingalignment, at locating and positioning pin 67 is inserted into alignedopenings in these'parts, the top of the pin being inserted in an opening68 in the housing 1. The, pin is prevented from emerging downwardlybythe bottom cap 69 which is held in place by a lock ring 70 in anannular-groove '71 in the housing '1. Set screws 72 in the bottom capmay be employed to exert a pressure against the cap69 and the lock ring70, I

A rotary tool such as a grinding wheel, sander or wire brush, indicatedat 73 is secured on the lower threaded end of the hollow spindle orshaft 33 by means of a nut and washer 74-75 which, when tightened, locksthe tool against the wheel collar 40 which is also threaded on the t Thegovernor mechanism includes a governor top. plate p 47 carryingaplurality of pivoted weights 47 a free floating governor bottom plate48-and a governor body 49, the top plate 47 and the body 49 beingsecured together by screws 50. The governor top plate 47 is providedwith a plurality of radial inwardly extending recesses 51 within 7 whichare pivotally'carried governor weights 47' eccentrically mounted on the.pins 52. These weights are Sincethe weights are relieved, their centerof gravity will be located above the pins and the weights under theaction of centrifugal forceand moving outwardly and downwardly willapply a downward force on the governor wear plate 54 which is seated onthe governor bottom plate 48, thus tending to move the governor bottomplate downwardly but such downward movementis resisted by the spring 84through the pin 82 which bears upon the upper end of the spring 84. Thisdownward movement of the governor bottom plate under the influence ofthe governor weights decreases the air gap between its lower surface andthe upper surface of thetop end plate 35, thus restricting the how offluid pressure through. the inlet bores 6t ofthe upper end plate and tothe rotor.

When a forcebalance is reached between the action of the governorweights and the reaction of the spring 84,

the top plate 47. will settle, and maintain a constant orifice or spacethrough which the incoming fluid pressure to the rotor can be meteredand thus control the r.p.m.- of the rotor. It is understood that theabove describes the action whenflthe motor has reached an idling speedWhlCh will be maintained until a load is applied to the motor. Theapplication of a load will'reduce the speed I (ofthe motor which ofcourse reduces the centrifugal force exerted upon the. governor weights,allowing the bottom plate 48 to move upwardly in response to thecompression force of the spring '84; As a resultof this action, the airgap between the governor bottom plateand the top end plate 18 increasedwhich allows more incoming fluid pressure to flow to the motor tomaintain its power output.

The idlingspeed of the motor is conveniently adjustable hy resetting thegovernor adjusting screw 86. In this connection, a lock screw may beinserted in the lower end of the spindle to abut and lock the set screw$6 in its adjusted position. I

The dead hollow handle or grip 4, illustrated in section in FIGURE 1,also serves as a convenient lubricant reservoir and is removablythreaded onto the boss 37 radially disposed on the housing 1 to providean oil reservoir 88 between the boss and the outer end of the handle.The outer end of the handle has a filler opening plugged at 89 and theboss 87 has an oil feed opening or duct 90 in which a wick-like packing91 and an oil feed control screw $2 are inserted. A restricted duct ororifice 93 communicates with the interior of the governor chamber 46 andwith the duct 90 to feed oil to the chamber 46. The flow of oil into thechamber is controlled by turning the screw 92 in either direction or itcan be entirely out ofi by tightening the screw against the end of theboss 87.

In use the invention may be described as follows:

When a source of fluid pressure, such as compressed air, is connected tothe inlet bushing in the handle 3 with the throttle valve in closedposition, air is prevented from entering the motor and the tool isinoperative.

To start the tool, the valve control plunger 26 is pushed axiallyinwardly (FIGURE 5) which action causes the plunger to move to the rightas it rides along the inclined or cam surface 22, thus unseating thevalve 6 and allowing fluid pressure to enter the governor chamber 46through the duct 15. With the governor unit in its maximum open positionunder pressure exerted by the spring 84-upon the pin 82, the maximumvolume of air enters the motor to start the rotor 31.

The flo-"w of air pressure from the governor chamber to the motorfollows a path between the governor bottom plate 48 and the upper faceof the top end plate 35 thence through the openings 60 and along recess61 into the rotor bores 41 and slots 42 behind the blades. The live airthen will travel through slots 44 and into the pockets formed betweenthe rotor and the liner 30 and the rotor blades 43.

Since the rotor is located eccentric to the bore of the liner 30 and hasminimum clearance with the liner at 32, the volume of the pocketsbetween adjacent blades Will vary from a minimum just beyond the point32 and the first blade in a clockwise direction, as in FIGURE 5, whichrepresents the intake pocket, to the next pocket between the said firstblade and the next blade which represents the expansion pocket.Following the blades in order in a clockwise direction, the next pocketmay be defined as the working pocket, while the final pocket representsthe exhaust position of the rotor wherein this pocket opens first to theexhaust slots in group G and then into the slots in group G in the liner36. From the outer surface of this portion of the liner, the air may beexhausted through openings in the housing (not shown).

With the flow as described above and due to the eccentric mounting ofthe rotor in the liner, it will be seen that the differential in airpressure on two adjacent rotor glades which are presenting varying areasfor the air pressure to react upon, constitutes the force that causesrotation of the rotor.

The air inlet, cut-0E and expansion timing is controlled by the designand location of the inlet openings to the rotor, while the exhausttiming and the-exhaust passages are located and designed for maximumefficiency with the minimum use of air.

Various changes may be made in the details of construction andarrangement of parts of the invention without departing from the spiritthereof or the scope of the appended claims.

I claim:

1. In a pneumatically operated tool, a housing, -a liner in the housing,a rotor rotatable in the liner, means for communicating fluid pressureto the rotor, governor means rotatable with the rotor and operable inresponse to the rate of rotation of the rotor to vary the volume of airto the rotor, a governor carrier body secured to the rotor, saidgovernor means including a pair of relatively movable governor platesarranged in axially spaced relation, an intermediate plate looselydisposed between said spaced plates, and centrifugally responsive meanson one of said paired plates for pressing said intermediate plate intofacial con-tact with the other of said paired plates, and means forexhausting spent fluid pressure from the tool.

2. In a pneumatically operated tool, a housing, a liner in the housing,a rotor rotatable in the liner and mounted therein with its axis ofrotation eccentric to the axis of the rotor liner, means forcommunicaitng fluid pressure to the rotor, governor means rotatable withthe rotor and operable in response to the rate of rotation of the rotorto vary the volume of air to the rotor, a governor carrier body securedto the rotor, said governor means including a pair of relatively movablegovernor plates arranged in axially spaced relation, an intermediateplate loosely disposed between said spaced plates, and centrifugallyresponsive means on one of said paired plates for pressing saidintermediate plate into facial contact with the other of said pairedplates, and means for exhausting spent fluid pressure from the tool.

3. In a pneumatically opeated tool, a housing, a liner in the housing, arotor rotatable in the liner, means for communicating fluid pressure tothe rotor, governor means rotatable with the rotor and operable inresponse to the rate of rotation of the rotor to vary the volume of airto the rotor, a governor carrier body secured to the rotor, saidgovernor means including a pair of relatively movable governor platesarranged in axially spaced relation, an intermediate plate looselydisposed between said spaced plates, and centrifugally responsive meanson one of said paired plates for pressing said intermediate plate intofacial contact with the other of said paired plates, means operatingthrough said governor carrier body for exerting a selected axialpressure against and toward said governor means to control the volume offluid pressure passing into the rotor, and means for exhausing spentfluid pressure from the tool.

4. In a pneumatically operated tool, a housing, a liner in the housing,a rotor rotatable in the liner and mounted therein with its axis ofrotation eccentric to the axis of the rotor liner, means forcommunicating fluid pressure to the rotor, governor means rotatable withthe rotor and operable in response to the rate of rotation of the rotorto vary the volume of air to the rotor, a governor carrier body securedto the rotor, said governor means including a pair of relatively movablegovernor plates arranged in axially spaced relation, an intermediateplate loosely disposed between said spaced plates, and centrifugallyresponsive means on one of said paired plates for pressing saidintermediate plate into facial contact with the other of said pairedplates, means for exhausting spent fluid pressure from the tool, andmeans operating through said governor carrier body for exerting aselected axial pressure against and toward said governor means tocontrol the volume of fluid pressure passing into the rotor.

5. In a pneumatically-operated tool, a housing, a liner in the housing,a rotor rotatable in the liner, means for communicating fluid pressureto the rotor, governor means rotatable with the rotor and operable inresponse to the rate of rotation of the rotor to vary the volume of airto the rotor, a governor carrier body secured to the rotor, saidgovernor means including a pair of relatively movable governor platesarranged in axially spaced relation, a wear plate loosely disposedbetween said spaced plates, centrifugally responsive means on one ofsaid paired plates for pressing said Wear plate into facial contact withthe other of said relatively movable plates to urge it into the path ofthe fluid pressure entering the rotor, said centrifugally responsivemeans including a plurality of pivoted weights eccentrically andradially mounted in said one paired plate to exert a pressure againstsaid Wear plate and said other paired plate in response to a centrifugalforce applied to said governor whereby to control the flow of fluidpressure to the rotor, and means for exhausting spent fluid pressurefrom thetool.

6. In a pneumatically operated tool, a housing, a liner in the housing,a rotor rotatable in the liner, means for communicating fluid pressureto the rotor, governor means rotatable with the rotor and operable inresponse to the rate of rotation of the rotor to vary the volume of airto the rotor, a governor carrier body secured to the rotor, saidgovernor means including a pair of relatively movable governor platesarranged in axially spaced relation, a wear plate loosely disposedbetween said spaced plates, centrifugally responsive means on one ofsaid paired plates for pressing said'wear plate into facial contact withthe other of said relatively movable plates to urge it and I said otherplate into the path of the fluid pressure entering the rotor, saidcentrifugally responsive means including a plurality of pivoted weightseccentrically and radially mounted in said one paired plate to exert apressure against said wear plate and said other paired plate in responseto a centrifugal force applied to said governor whereby to control theflow of fluid pressure to the rotor, said Weights each being relieved toraise its center of gravity for effective downward pressure contact withthe wear plate under the influence of centrifugal force, and

means for exhausting spent fluid pressure from the tool.

7. A fluid pressure operated tool including a housing, a governorchamber and a rotor chamber in said housing, a rotor eccentrically androtatably carried in said last chamber, a fluid pressure inlet to saidfirst chamber, ducts connecting said chambers to communicate fluidpressure to said rotor, centrifugally responsive governor means in thegovernor chamber and rotatable with said rotor, fluid pressure volumecontrol means responsive to said governor to thereby control the rate ofrotation of the rotor, said last named means comprising a pair ofrelatively movable governor plates arranged in axially spaced rela-'tion in the path of movement of fluid pressure from said governorchamber to the rotorchamber and directly responsive to said governormeans to regulate and control the volume of fluid pressure passing intosaid rotor chamher, and means for exhausting spent fluid pressure fromthe rotor chamber.

8. In a pneumatically operated tool, a housing, a rotor rotatable in thehousing, a governor chamber in the housing, a fluid pressure inlet inthe governor housing, means for progressively communicating fluidpressure from the governor chamber to the rotor, said means comprising aseries of openings therebetween, governor means rotatable with the rotorand operable in response to the rate of rotation of the rotor to varythe volume of fluid pressure to the rotor, a governor carrier bodysecured to and rotatably with the rotor, said governor means including apair of relatively movable axially spaced apart governor platesextending radially closely toward but spaced at their circumferencesfrom the wall of the governor housing to provide a passageway for fluidpressure to said series of openings into the rotor, centrifugallyresponsive means on one of the paired plates for exerting pressure onthe other of said plates whereby to vary the volume of fluid flow intosaid openings, and means for exhausting spent fluid pressure from thetool.

9. In a pneumatically operated tool, a housing, a rotor rotatable in thehousing, a governor chamber in the housing, a fluid pressure inlet inthe governor housing, means for progressively communicating fluidpressure from the governor chamber to the rotor, said means comprisingan opening therebetween, governor means rotatable with the rotor andoperable in response to the rate of rotation of the rotor to vary thevolume of fluid pressure to the rotor, a governor carrier body securedto and, rotatable with the rotor, said governor means including a pairof relatively movable axially spaced apart governor plates extendingradially closely toward but spaced at their circumferences from the wallof the governor housing to provide a passageway for fluid pressure tosaid opening into the rotor, centrifugally responsive means on one ofthe paired plates for exerting pressure on the other of said plateswhereby to vary the volume of fluid flow into said opening, and meansfor exhausting spent fluid pressure from the tool.

10. In a pneumatically operated tool, a housing, a roto rotatable in thehousing, a governor chamber in the housing, a fluid pressure inlet inthe governor housing, means for progressively communicating fluidpressure from the governor chamber to the rotor, said means comprisingan opening therebetween, governor means rotatable with the rotor andoperable in response to the rate of rotation of the rotor to vary thevolume of fluid pressure to the rotor, a governor carrier body securedto and rotatable with the rotor, said governor means including a pair ofrelatively movable axially spaced apart governor plates extendingradially closely toward but spaced at their-circurnferences fromthe wallof the governor housing to provide a passageway for fluid pressure tosaid opening into the rotor, the lowermost plate being slotted radiallyinwardly from its peripheral edge, said slots adapted to pass acrosssaid opening communicating the governor chamber with the rotor as therotor rotates, centrifugally responsive means on one of the pairedplates for exerting pressure on the other of said plates whereby to varythe volume of fluid flow into said opening, and means for exhaustingspent fluid pressure fromthe tool.

11. In a pneumatically operated tool, a housing, a rotor rotatable inthe housing, a governor chamber in the housing, a fluid pressure inletin the governor housing,

- means for progressively communicating fluid pressure from the governorchamber to the rotor, said means comprising an opening therebetween,governor means rotatable with the rotor and operable in response to therate of rotation of the rotor to vary the volume of fluid pressure totherotor, a governor carrier body secured to and rotatable'with the rotor,said governor means including a pair of relatively movable axiallyspaced apart governor plates extending radially closely toward butspaced at their circumferences from the wall, of the governor housing toprovide a passageway for fluid pressure to, said opening into; therotor, centrifugally responsive means on one of the paired plates forexerting pressure on the other of said plates whereby to vary the volumeof fluid flow into said opening, and means for exhausting spent fluidpressure from the tool, said last named means including a plurality ofelongate radially disposed exhaust openings in said rotor anda pluralityof staggered ex haust slots in the rotor chamber adapted to be traversedby said radial openings during rotation of the rotor.

References Cited in the tile of this patent UNITED STATES PATENTS KarlenApr. 6, 1954

